Ethnicity estimate is based on the data Ancestry have and the methods they use to compare our results to that data. When AncestryDNA launched in 2012, they compared our DNA against 22 possible regions. Since then, additional data and advances in science have enabled AncestryDNA to identify dozens of new regions and improved their ability to determine how likely it is a region is part of our past. DNA research is a fast paced, rapidly expanding field, and we can expect to see additional updates as DNA science evolves.